This invention relates to tubing coupling systems, and specifically to an improved tubing coupling or adapter apparatus and method that combines improved ease of assembly with the ability to visually confirm the assembly of the tubing with the coupling or adapter. The present invention lends itself to various applications, including liquid and gas tubing systems which are used in a wide range of industrial and agricultural installations, including irrigation systems. The invention is useful with tubing in numerous lengths, diameters, wall thicknesses, strengths, and configurations (including without limitation, tubing having cross-sections that are round, square, rectangular, or oval). Such tubing can include, at its opposite extremity, any of a variety of fittings, including a second one of the claimed improved tubing coupling, a hose end, an elbow (or "ell"), or any of a wide range of devices that will make themselves readily apparent to persons of ordinary skill in the art.
Elastic tubing (such as polyethylene tubing) is sometimes attached by the use of barbed fittings on adapters and couplings, such as depicted in FIG. 1. To make the desired connection, a user typically has a supply of adapters/couplings 2 and separate retaining rings 4. Prior art rings 4 and couplings 2 are not configured so that the ring is retained on the coupling prior to attachment to tubing. As a result, even if a manufacturer attempts to assist the end user by placing the rings 4 on the couplings 2, the rings typically fall off the couplings 2 during transit or handling, and the user receives a loose pile of rings and couplings. Thus, instead of a simple single assembly which is usable by picking the single assembly up and attaching tubing to it, the user must fumble with locating the adapter/coupling 2, locating one or more retaining rings 4, assembling the components to each other, and finally inserting tubing (not shown) over a barbed fitting 6 on the adapter and under interior barbs 8 on the retaining ring 4. The barbs 8 can then be slid over the tubing toward the exterior barbs 6 to help "lock" the tubing on the adapter/coupling 2.
In certain assemblies, it can be difficult to determine the position of the tubing on the adapter/coupling once the retaining ring has been "locked" into place. Thus, it may be difficult or impossible to determine whether the tubing is properly positioned, or if it has dangerously loosened over time, without removing the lock ring. This is especially important for those applications where the pressure from the fluid pumped through the tubing tends to push the tubing off the adapter.
In certain applications, such as irrigation systems, these assemblies are commonly used to connect tubing or hose to other components of the system. Among other things, such connected tubing or hose may have, at its other extremity, another coupling, a hose end, an ell, or some other fitting. Typically, the more quickly, easily, and reliably those system components can be connected to each other (via such a coupling or adapter), the more economic the installation becomes. Maintenance of the system can similarly benefit from better coupling apparatus and methods.